Why do electrons continue to move in the same direction in an electric circuit with a potential difference?
In a circuit with a potential difference, electrons move in the same direction due to the influence of the electric field force. When the power supply is turned on, a large amount of negative charge (electrons) accumulates at the negative pole of the power supply, while a large amount of positive charge accumulates at the positive pole. These charges are separated within the power supply due to chemical reactions or other energy conversion processes, resulting in a potential difference, or voltage, between the two ends of the power supply.
When the circuit is closed, the free electrons in the conductor are subjected to the force of the electric field and begin to move from the negative pole of the power supply to the positive pole. This electric field force is generated by the potential difference between the two ends of the power supply, and it drives the electrons to move along the conductor in a specific direction, that is, from low potential (negative pole) to high potential (positive pole). Although the electric field inside the conductor may not be completely uniform, it can still effectively guide the electrons to move in the same direction.
In addition, the free electrons in conductors, under the action of electric field force, although their actual motion path may be tortuous, due to a large number of electrons subjected to forces in the same direction, they exhibit a phenomenon of directional movement as a whole. Although the speed of this directional movement is very slow relative to the speed of light, it is sufficient to form the current we observe.
In summary, the reason why electrons move in the same direction within a circuit with a potential difference is due to the electric field force provided by the power supply. This force prompts free electrons to overcome internal resistances, such as the attraction of atomic nuclei and collisions with other electrons, and move unidirectionally along the conductor.
